Just wanted to mention I have a very strong immunity when it comes to bacteria and viruses...I just don't seem to get sick, but when it comes to yeast I can't tolerate any carbs, besides a little fruit and the carbs in raw dairy. Anything else makes me feel off and fatigued...yet even if I eat carbs, I can go day after day feeling low and eating more carbs but my immunity still stays up when it comes to bacteria and viruses. So in my case its separate from my immunity which makes me think its some hormonal imbalance like Andy says.